Why is the Guitar tuned like this?

It may not make sense to you at first, and you might just never think of it.

The guitar is tuned the way it is for good physical-mechanical reasons. You have four fingers on your fingering hand, so the guitar strings are tuned 5 frets apart (except for the B string). That means you can move up the scale of notes fret by fret until you come to the fifth fret. That one is tuned the same as the next higher string.

As you move up the frets the pitch increases by semi-tone increments. To play the chromatic scale you go up four frets and then move to the next string.

This allows you to place your fingers along the frets, one finger per fret, in what we might call the “classic position”. The tuning of the guitar is based on this idea. It allows you to play up to two octaves of popular scales in the open position without moving your hand from the classic setup.

In other words it is tuned to take advantage of the four finger classic setup.